<template>
  <div>
    <School ref="school"/>
    <button @click="add">点击增加一个练习</button>
  </div>
</template>



<script>
  import School from "./components/School.vue"
  export default {
    name: 'App',
    components: {
      School,
    },
    methods: {
      add(){
        return this.$refs.school.num++
      }
    }
  }
</script>

<style>

</style>